Crate V50 now the relay?

[pontiacpete]

I posted earlier about this amp, it had a fast acting diode that was shorted. I was hoping that replacing it would have fixed it, but no. The SMPS is now working and all the required voltages are coming out of it. However, when I hook up the pre amp with no tubes and try to start it on a current limiter bulb, the bulb flashes brightly a few times and then nothing. When disconnecting the pre amp the voltages age are still coming out of the power supply, so, no damage.
I replaced D7 because it was measuring a low resistance one way, something like a few hundred ohms. But that did nothing.
I checked all the caps and diodes on the board some in circuit and some out.
Now I'm thinking about the 2 relays, is the flashing of the bulb a sign that the relay is trying to work? and therefore should be replace?
Also, relay 1A G6S-2-12v doesnt seem to made anymore, but the 24v one is,,,would this be a suitable sub?
thanks for taking the time to read.
pete

[Pedro Vecino]

Continous flashes on the limiter are due to the switching power supply (I dŽont know the exact name in english). Today, working with a V33 is what I have seen...

[Enzo]

If you are not blowing fuses get rid of the light bulb. Switchers may noy be very happy running with bulbs anyway.

If all voltages are present with no preamp, what happens when you connect the preamp but still no tubes?

[pontiacpete]

thanks guys for helping me get over the big hump of just turning it on and seeing what happens. It's working fine. duh, it was the UF2010 after all.

[pontiacpete]

It's back. Same diode D104 shorted. It worked for 3 rehearsals. I'm not sure what to think about this. The first time it showed up here one of the 6l6's was shot along with D104, so that seemed like a reasonable enough cause for the breakdown.
So,I have a few questions with the hope that someone is still interested in helping.
This time only D104 is shorted, and the new 6L6's are still working. I replaced D104 and it fires up without a problem. The plates are at 430v and they are drawing 30ma.
My question is what, voltage should CW8 be adjusted at?
Also, since D104 is in the middle of the HV winding, does it make sense to change out C107? Could it be failing?
Or would it be a good idea to change C23 and C24? Could they be causing the amp to lose bias over extended operation, perhaps at high volume?
Does anyone have any advice here? As you can see I'm stabbing in the dark at this point.
thanks

[Enzo]

If D104 shorts, I'd be changing D103, D105 as well. They are all operating in series more or less. My inner voice says ignore the caps, but for the price of three caps, you can be assured it was not the caps.

CW8 appears to be a balance control for the phase inverter. I look at it and think, gee why not set it to zero, leaving the 82k and 100k plate loads we see all the time. Then if I felt frisky I'd probably twiddle it and set it by ear. If you feel all scientific, apply a sine wave at the FX return and diddle with the control while watching the output on a scope, looking for best symmetry.